Power tool with means for obtaining product use information

ABSTRACT

A charging apparatus for charging a battery comprising a current source for providing current to the battery, a controller connected to the battery and to the current source for controlling charging of the battery, and a memory connected to the controller for storing information about the battery. The memory may also store information about the charging apparatus. Preferably, the memory is a nonvolatile memory, such as E 2 PROM. Also disclosed are a battery having a memory for storing information, a power tool having a memory for storing information about the tool, and a reading apparatus for reading the information stored in the memory of the charger, battery and/or power tool.

This is a request for filing a continuation application under 37 CFR§1.53(b), of prior application Ser. No. 09/292,165, filed on Apr. 15,1999 now U.S. Pat. No. 6,218,806 entitled Method and Apparatus forObtaining Product Use Information.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is based upon and claims priority under 35 USC §119 and 37 CFR § 1.78 of copending U.S. provisional applications Ser.No. 60/089,066, filed on Jun. 12, 1998, and Ser. No. 60/087,896, filedon Jun. 3, 1998.

FIELD OF THE INVENTION

This invention relates generally to a method and apparatus for obtainingproduct use information and more particularly, for obtaining useinformation of components included in a rechargeable battery system.

BACKGROUND OF THE INVENTION

Rechargeable battery systems include three main components: (1) arechargeable battery or battery pack; (2) a charger for charging thebattery; and (3) a device powered by the battery, such as portable powertools and certain kitchen and domestic appliances. Knowledge of how auser actually uses and interacts with each component can provide usefulinsights, which can in turn be implemented in future product designs.

Typically, such information is derived from actual interviews withusers, either individually or in groups. However, the informationderived from these interviews is usually information relating to theuser's perception of his use patterns, which are often subjective andinaccurate.

It is thus an object of the invention to provide a method and apparatusfor obtaining actual product use information.

SUMMARY OF THE INVENTION

In accordance with the present invention, a charging apparatus forcharging a battery comprising a current source for providing current tothe battery, a controller connected to the battery and to the currentsource for controlling charging of the battery, and a memory connectedto the controller for storing information about the battery. The memorymay also store information about the charging apparatus. Preferably, thememory is a non-volatile memory, such as E²PROM.

Additional features and benefits of the present invention are described,and will be apparent from, the accompanying drawings and the detaileddescription below.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate preferred embodiments of theinvention according to the practical application of the principlesthereof, and in which:

FIG. 1 is a circuit schematic diagram of a battery charger according tothe present invention;

FIG. 2 is a circuit schematic diagram of a battery according to thepresent invention;

FIG. 3 is a circuit schematic diagram of a cordless tool according tothe present invention; and

FIG. 4 is a block diagram of a data reader according to the presentinvention.

DETAILED DESCRIPTION

The invention is now described with reference to the accompanyingfigures, wherein like numerals designate like parts. All the teachingsof the Saar U.S. Pat. Nos. 4,388,582 and 4,392,101 are herebyincorporated by reference into this specification.

Referring to FIG. 1, a battery 10 is connected to a charger 20. Battery10 comprises a plurality of battery cells 11 connected in series, whichdictate the voltage and storage capacity for battery 10. Battery 10includes three battery contacts: first battery contact 12, secondbattery contact 13, and third battery contact 14. Battery contact 12 isthe B+ (positive) terminal for battery 10. Battery contact 14 is the B−or negative/common terminal. Battery contact 13 is the S or sensingterminal. Battery contacts 12 and 14 receive the charging current sentfrom the charger 20 (preferably from current source 22, as discussedbelow) for charging the battery 10.

As shown in FIG. 1, the battery cells 11 are connected between thebattery contacts 12 and 14. In addition, preferably connected betweenbattery contacts 13 and 14 is a temperature sensing device 15, such as anegative temperature co-efficient (NTC) resistor, or thermistor, R_(T).The temperature sensing device is preferably in closer proximity to thecells 11 for monitoring of the battery temperature. Persons skilled inthe art will recognize that other components, such as capacitors, etc.,or circuits can be used to provide a signal representative of thebattery temperature.

Battery 10 may also comprise an identifier as known in the prior art, sothat charger 20 can identify the type and capacity of the battery, andcharge accordingly.

The charger 20 preferably comprises a controller 21, which in turnincludes positive terminal (B+) 16 and negative (B−) terminal 17, whichare coupled to battery 10 via battery contacts 12 and 14, respectively.The positive terminal may also act as an input, preferably ananalog/digital input, in order for the controller 21 to detect thebattery voltage. In addition, the controller 21 may include anotherinput TC, preferably an analog/digital input, which is coupled to thetemperature sensing device 15 via the third battery contact 13 (S). Thisallows the controller 21 to monitor the battery temperature. Controller21 may include a microprocessor 23 for controlling the charging andmonitoring operations. Controller 21 may control a current source 22that provides current to battery 10. This current may be a fast chargingcurrent and/or an equalization current. Current source 22 may beintegrated within controller 21.

A switch SW1 may be connected to controller 21 to manually selectcharging processes or modes, such as a fast charging mode and a refreshmode.

A memory 25 is preferably connected to the controller 21. Preferably,the memory 25 is a non-volatile memory such as E²PROM. Accordingly,controller 21 may read and/or write in memory 25. Controller 21 maystore in memory 25 information related to the battery, such as type,capacity, charging process, etc. Similarly, controller 21 may store inmemory 25 information related to the charger. For example, controller 21may store information such as number of NiCd batteries charged, numberof NiMH batteries charged, number of times switch SW1 was on oractivated (i.e., the number of times the refresh mode was selected),number of times the charging process was delayed to allow cooling of thebattery, etc.

Preferably controller 21 can designate a string of memory slots, or“buckets,” for storing related information. For example, in order tosave information on initial battery temperature, a string of memoryslots of memory 25 may be organized into buckets, each bucketrepresenting a range of initial battery temperatures. Accordingly, abucket may be designated for initial temperatures below 20° C. A secondbucket may be designated for initial temperatures between 20° and 30°,and so on. Accordingly, for example, if a battery 10 with an initialtemperature of 43° C. is inserted into charger 20, controller 23 wouldread the bucket corresponding for initial temperatures between 40° and45°, increase the read value and store the new value in the bucket.

Similar buckets may be established for other information, such as chargetermination process, i.e., number of times minus-delta-V was used toterminate charging, number of times temperature change rate was used toterminate charging, etc.

Persons skilled in the art will recognize that controller 21 may storein memory 25 any type of desired information, provided the controller 21receives the proper input. For example, a signal 24 originating from thepower supply representative of the voltage received from an outlet orgenerator, i.e., the mains voltage, may be received by controller 21.Controller 21 can then determine and store, for example, the number oftimes the mains voltage was below 90 volts or above 130 volts.

Similarly, controller 21 may also store into memory 25 the amount oftime a battery 10 is connected to charger 20. Such information is usefulto determine actual conditions of use, which can then be trusted indesigning future chargers.

Persons skilled in the art will recognize that any information relatedto the battery charging process and/or charger may be stored in memory25 so long as controller 21 receives the proper input and a large enoughmemory is provided.

In order to analyze the information, it must be downloaded from charger20. Referring now to FIGS. 1 and 4, such operation may be accomplishedby connecting the charger 20 to a reader 50 and/or a computer 53, whichhas memory 53M. Reader 50 may have contacts 54, 55 and 56 which connectto the different terminals of charger 20. Reader 50 may also have amicroprocessor 51 for controlling the communications between charger 20and reader 50. A memory 52 may also be provided in reader 50 for storingthe contents of memory 25, if so desired. This allows the analyst todownload the information from charger 20, without carrying a separatecomputer 53, and then later downloading the contents of memory 52 intomemory 53M of computer 53. Reader 50 may also contain enough memory tostore the information downloaded from several chargers 20. Reader 50 maybe connected tote serial or parallel ports of computer 53, for example.

Controller 21 has at least one line for transmitting the contents ofmemory 25. Preferably, this line is the TC line. Controller 21preferably conducts a “data dump” operation, where the information ofmemory 25 is directly transmitted without further intervention fromcontroller 21. Controller 21 may send the information to reader 50 aftera hand-shaking routine between reader 50 and controller 21 is conducted.Preferably, controller 21 sends the information via the TC lineaccording to a serial communication scheme. Reader 50 then receives theinformation, stores it into memory 52 and/or sends it to computer 53 foranalysis.

FIG. 2 illustrates a battery 30 according to the present invention,where like numerals represent like parts. The main difference betweenbattery 10 and battery 30 is that battery 30 has been equipped with acontroller 31, preferably connected to terminals 12, 13 and 14.Controller 31 may include a microprocessor 32 for controlling thesensing and memory operations, as discussed below.

A memory 33 is preferably connected to the controller 31. Preferably,the memory 33 is a non-volatile memory such as E²PROM. Accordingly,controller 31 may read and/or write in memory 33. Controller 31 maystore in memory 33 information related to the battery, such astemperature, length of charging process, etc., in a manner similar tothat explained above.

A bias pull-down resistor 34 may be disposed between terminals 13 and14.

Referring now to FIGS. 2 and 4, the information from memory 33 may bedownloaded by connecting the battery 30 to a reader 50 and/or a computer53. Reader 50 may have contacts 54, 55 and 56 which connect to theterminals 12, 13 and 14 of battery 30.

Reader 50 and controller 31 may conduct a hand-shaking routine to inducecontroller 31 into transmitting the information stored in memory 33.Such a routine could be as simple as pulling up the bias on the lineconnected to the sensing terminal 13. Controller 31 would sense the biaspull-up and proceed to transmit the information. Preferably, controller31 conducts a data dump operation, where the information of memory 33 isdirectly transmitted without further intervention from controller 31.Controller 31 may send the information to reader 50 according to aserial communication scheme. Reader 50 then receives the information,stores it into memory 52 and/or sends it to computer 53 for analysis.Reader 50 may also contain enough memory to store the informationdownloaded from several batteries 30.

FIG. 3 illustrates a tool 40 according to the present invention. Tool 40comprises terminals 46 and 48 for receiving power from a batteryconnected thereto, and tool circuits 41 connected to terminals 46 and48. Tool circuits 41 may include power regulation circuits, motorcircuits, etc. A controller 42 is preferably connected to terminals 46and 48. Controller 42 may include a microprocessor 43 for controllingthe sensing and memory operations, as discussed below. Controller 42 mayalso be connected to a terminal 47 to be used for transmittinginformation, as discussed below. A bias pull-down resistor 45 may bedisposed between terminals 47 and 48.

A memory 44 is preferably connected to the controller 42. Preferably,the memory 44 is a non-volatile memory such as E²PROM. Accordingly,controller 42 may read and/or write in memory 44. Controller 42 maystore in memory 44 information related to the tool 40, such as tooltemperature, length of use, number of times the tool has been turned on,etc., in a manner similar to that explained above. Controller 42receives the desired information from the tool circuits 41.

Referring now to FIGS. 3 and 4, the information from memory 33 may bedownloaded by connecting the tool 40 to a reader 50 and/or a computer53. Reader 50 may have contacts 54, 55 and 56 which connect to theterminals 46, 47 and 48 of battery 30.

Reader 50 and controller 42 may conduct a hand-shaking routine to inducecontroller 42 into transmitting the information stored in memory 44.Such a routine could be as simple as pulling up the bias on the lineconnected to the terminal 47. Controller 42 would sense the bias pull-upand proceed to transmit the information. Preferably, controller 42conducts a data dump operation, where the information of memory 44 isdirectly transmitted without further intervention from controller 42.Controller 42 may send the information to reader 50 according to aserial communication scheme. Reader 50 then receives the information,stores it into memory 52 and/or sends it to computer 53 for analysis.Reader 50 may also contain enough memory to store the informationdownloaded from several tools 40.

In order to provide more accurate use information, it is preferable thatmemories 25, 33 and 44 are pre-programmed with identification codes orserial numbers that are downloaded by reader 50. Using thepre-programmed identification code, computer 53 can then better analyzethe downloaded information by disregarding old information, comparinguse between downloads, etc.

Persons skilled in the art will recognize that the use information canalso be used to detect instances of abuse.

Persons skilled in the art may recognize other alternatives or additionsto the means or steps disclosed herein. However, all these additionsand/or alterations are considered to be equivalents of the presentinvention.

1. A power tool system comprising: a power tool including a first memoryfor storing use profile information about the power tool, a readerapparatus connectable to the power tool for downloading the stored useprofile information from the first memory, the reader apparatuscomprising a second memory for storing the stored use profileinformation downloaded from the first memory, and a computer separatefrom the reader apparatus and connectable to the reader apparatus, fordownloading the downloaded information from the second memory of thereader apparatus, the computer comprising a third memory for storing thedownloaded information from the second memory.
 2. The power tool systemof claim 1, wherein the stored information comprises at least one of thegroup consisting of tool temperature, length of use, and number of timestool has been turned on.
 3. The power tool system of claim 1, whereinthe stored information comprises length of use.
 4. The power tool systemof claim 1, wherein the memory is non-volatile.
 5. The power tool systemof claim 1, wherein the memory comprises an E₂PROM memory.